1. Field
Apparatuses consistent with exemplary embodiments relate to an image pickup apparatus including lens elements having different diameters.
2. Description of Related Art
Because thicknesses of mobile devices, such as mobile phones, are being continuously reduced, there is a demand to reduce thicknesses of optical systems of cameras disposed in mobile devices. When a thickness of an optical system is reduced, a focal length of the optical system is reduced, and thus a size of an image sensor is reduced. As a result, quality of an image picked up via the optical system may be deteriorated. The reason for the deterioration is that a number of pixels decreases as the size of an image is reduced. However, if a size of pixels of an image sensor is reduced in correspondence to the size reduction of the image sensor, images having sufficiently high resolutions may be obtained. Therefore, various attempts are being made to reduce pixel pitch of an image sensor. For example, a pixel pitch of current image sensors has been reduced to about 1 μm.
Meanwhile, because a thickness of a camera in a mobile device is limited, a unifocal lens with a short focal length is generally employed instead of a zoom lens with variable focal lengths. Therefore, it may be difficult for a camera of a mobile device to provide a zooming function. Most cameras in mobile devices provide a digital zooming function instead of an optical zooming function. In other words, because digital zoom is a function for magnifying a portion of an original image picked up by a camera merely via signal processing, quality of a magnified image may be deteriorated as an angle of view of the magnified image is narrowed.